Thread-measuring mechanism for sewing machines



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J. H. REED THREAD MEASURING MECHANISM FOR SEWING MACHINES Filed Oct. 19. 1922 2 Sheets-Sheet 2 av. 54, Gag b 73L H-ya Patented Oct. 16, 1928.

UNITED STATES PATENT OFFICE.

JAMES H. REED, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY,

A CORPORATION OF NEW JERSEY.

THREAD-MEASURIN G IVIECHANISM FOR SERVING MACHINES.

Application filed October 19, 1922. Serial No. 595,580.

This invention relates to thread measuring mechanism for sewing machines.

The invention has for its object to provide improved mechanism for drawing from a source of supply an amount of thread necessary for the formation of each successive stitch, said mechanism being controlled by the thickness of the work and operating to measure the thread accurately in accordance with such thickness and to control the same in a reliable manner. I

The more particular objects of-the invention, together with means whereby the same may be carried into effect, will best be un derstood from the following description of one form and application thereof illustrated in the accompanying drawings. It will be understood, however, that the particular em.- bodimentof the invention "shown has been chosen for illustrative purposes merely, and that the invention, as defined by the claims hereunto appended, is by no means limited to the particular construction and application shown, but may assume other forms and be used in connection with machines of other types without departure from its spirit and scope.

In said drawings:

Fig. 1 is a side elevation, partly in section, of a substantially complete shoe sewing machine embodying the invention. v

Fig. 2 is a horizontal section, taken substantially on the line 22 of Fig. 1, the takeup and the upper threadclamp being omitted.

Fig. 3 is a section, taken substantially on the line 33 of Fig. 1, of the'lower thread clamp and its operating mechanism. 7 Figure 4 1s a detail frontelevation of the threadpull-off and the thread clamps.

Figure 5 is a detail section, taken substantially on the line 55, Figure 4, but showing the thread throughout. Figure 6 is a similar view showing the parts in a different position. 7

While the invention may be used in connection with sewing machines of other types it is herein shown as'applied to a shoe sewing machine of the character described in my prior application for Letters Patent filed March 10, 1922, Serial No. 542,666. Said machine comprises a'standard or base 15 supporting a head frame 16at its top, and below said head frame, in the front of the machine,

a rotatable born 17 for supporting the'work.

The various instrumentalities of the machine receive their several operative movements from a main shaft 18'journalled in the head, and a vertical shaft 19, journalled in said head and in the upright 15; The shaft 19 is operatively connected by gears 20 with the main shaft 18 to which power. is applied through a loose pulley 21 capable of being connected with said main shaft through a suitable clutch and stop mechanism 22. The particular stop mechanism herein shown is covered by another application, filed October 14, 1922, Serial No. 594,458, and will not be described in detail herein, as any suitable type of clutch or stop mechanism many of which are well known, may be employed. Thestitch forming instrumentalities comprise a vertically reciprocating needle23 and a discoidal shuttle 24 carried by the head above the work, and a whirl. or looper 25 located in the horn below the work. The needle 23 is straight and barbed and is carried by a needle bar 26 which is reciprocated by suitable connections with the main shaft 18. The whirl 25,-which is operated by mechanism hereinafter described, is adapted, when the needle is moved downwardly through the work, to place a loop of cop thread 27 in the connected with the main shaft 18, said shut tle and shuttle mechanism, as herein shown, being of the type covered by other applications filed, respectively, October 14, 1922, Serial No. 594,457, and October 18, 1922,

- Serial No. 595,266. In addition tothe stitch forming instrumentalities above described, there is provided at the base of the machine a main or stitch forming takeup 29, whose function it is to draw the needle loop over the shuttle 24 and down upon thework after the,

. shuttle has been passed therethrough, and a stitch setter 30, located in the horn, to set the stitch. The cop or needle thread 27 is drawn from a suitable source of supply (not shown) by the pull-ofi' hereinafter described, then cepasses through a wax pot 31, and thence leads successively to the takeup '29, through a hollow shaft 32 journalled in thebase of the horn, to the stitch setter 30, and finally v to the Whirl 25. The work is fed over the against the alinement with the thread horn as the stitching progresses by means of a suitable feed point 38, said feed point operating to advance the work between the formation of successive stitches, and while each stitch is being formed, said work is clamped to the horn by a presser foot 8% carried by a presser foot bar 35. The press er foot bar 35 is normally pressed downwardly by a strong spring 36, and is periodically lifted to permit the work to be fed by means of a bell-crank lever 37 which is actuated by a cam 38 on the main shaft 18. The whirl 25 is oscillated by means of intergeared shafts 39 the lowermost of which is geared to the shaft 82. The latter shaft carries at its lower end a pinion 40 which meshes with a gear 10 carrying a coaxial pinion 11. The pinion 11 coope ates with a rack 41 (see Figure 2) formed on a bar 12 guided in the base 15 and carrying at its rear end a cam roller 4:?) which cooperates with a cam 44': on the shaft 19.

Except in so far as they enter into combination with the mechanism hereinafter described, the parts above referred to specifically constiute no portion of. the present invention and may be of 7 any suitable form. They will, therefore, not be furt ier describec herein, as they are fully disclosed in my other applications above referred to, and the foregoing outline of their nature, arrangement, and function will be suilicie-nt for complete understanding of the invention herein claimed.

The thread pull-oft comprises a rod 45 guided for longitudinal movementin the base 15 and having at its forward end a thread engaging); notch 4C6 cooperating with stationary thread guides located respectively on opposite sides thereof. These thread guides, as shown, comprise alined openings 47 in a boss d8 formed on a plate 4:9 secured to the base 15, said boss being; suitably bored to receive and guide the end of the rod 45. Said rod 4 .5 is normally held with the bottom of the notch as in alinement with the guide openings 17, as shown in Figure 5, by means of a spring (if positioned between the front wall of the base 15 and a collar 65 fast on said rod, said spring tending; to move said rod rearwardly to an extent determined by the engagement of a second collar 66 thereon with the rear wall of said base. Longitudinal movement of said rod s5 action of the spring; 6% causes the the notch 46 to be moved out of guides 47, as shown in Figure 6, thereby pulling oft an amount of thread determined by the extent of such movement, the parts being suitably cut away, as indicated at C in Figures T and .5, to permit this movement without injury to the thread. The mechanism for so moving the rod 45 to an extent detcrmined by the thickness of the work on the horn 27 is preferably substantially as follows. 1

bottom of -wardly, to cause the block Pivoted at 50, to a suitable bracket 51 on the top of the head 16, is a lever 52 connected at one end with the prcsser foot bar 35. The oposite end of said lever is connected by linl: 58 with a slide 5e guided for longitudinal movement on a lever 55 pivoted at 56 to a support 57 on the base 15. The lever 55 is connected by a link 58 with a lug or collar 59 on the rack bar l2. Carried by the slide 54: is a plate 60, said plate being preferably adjustably secured to said slide, as by means of screws 61 one of which passes through an elon-' gated slot 62 in said plate.

JV hen the lever 55 is oscillated by its connection with the rack bar 42, the plate will engage a lug or collar 63 on the rod 45 and move said rod an amount depending upon the position of the slide 5d on the lever 55 and theadjustment of the plate 60'on said slide The position of the slide 54 on the lever 55' determines the elfective amplitude of movement of the plate 60, and is automatically controlled, in accordance with the thickness of the work, by its connection with the presser foot. The adjustment of'the plate 60 on the slide 54s determines the amount'of lost motion between said plate and the collar 63, this adjustment being effected manually for the purpose of controlling the pull-off in accordance with the length of stitch or otherwise.

Located respectively at opposite sides of the pull-off are upper and lowerthread clamps a i 67 and 68, the former being locatedbetween said pull-off and the source of thread supply, and the latter being located between said pulloff and the stitch forming; mechanism, The clamp 68 comprises a block secured to rod 69 guided for longitudinal movement in the base 15, said rod being normally forced rear- 68 to clamp the thread 27 against a fixed clamping member 70 on the plate l -.5), by means of a spring '21 in terposed between the front wall of the base 15 and a collar 72 fast on the rod, said rod being moved in the opposite direction, to sep rate the clamping member 68 from the clamp ing member 70, by means of a lever 73 which engages the rear of said rod, said lever being pivoted to the base '15 and being acted upon by a cam 74 on the shaft 19, The-clamp 67 is precisely similar in construction. and

operation to the clamp 68, being carried by a rod 7 5 which is moved in one direction to close the clamp by a spring 76, and in the opposite direction to open the clamp by a lever 77 000p crating with a earn? 8 on the, shaft 19.

The cams 7 4 and 78 are so designed and timed with respect to each other and the other working in 'strumentalities of the machine that when the pull-off is inactive the clamp 68 is open and the clamp 67 is closed, said clamp 67 serving as an anchor for the thread when the latter is acted upon by the take-up 29 and stitch setter 30. When the pull-off is operated, the clamp 68 is closed, thereby anchoring the thread for the action of said pull-off, and the clamp 67 at the same time opened, thereby permitting said pull-oil to draw the thread from the supply. Thereafter, as said pull-oil is returned to normal position, the clamp 67 is again closed, and the clamp 68 opened to permit the thread drawn from the supply by said pull-oii to be taken up and used by the stitch forming devices. The clamps 67 and 68 are thus operated alternatively, one being closed simultaneously with or just prior to the openingof the other, and vice versa, so that one or the other of said clamps is closed at all times, thereby exercising an uninterrupted control over the thread.

What I claim is 1. In a sewing machine, in combination, thread guiding means, a pull-ofi' member cooperating therewith, a lever, means for actuating the same, a slide guided on said lever and arranged to actuate said pull-ofi' member, a presser foot, a lever connected with said presser foot, and a link connecting said lever and slide whereby the movement imparted to the pull-off member by the slide is varied in accordance with the thickness of the work.

2. In a sewing machine, thread measuring mechanism comprising a pair of stationary thread guides, a pull-off member between said guides and having a thread engaging portion, a spring for holding said pull-off member with its thread engaging portion in alinement with said guides, a slide'having means for moving said pull-oft member in a direction transverse to the line connecting said guides, a lever on which said slide is guided, means for oscillating said lever, and a presser foot operatively connected with said slide, whereby the movement imparted to the pull-off member by the slide is varied in accordance with the thickness of the work.

3. In a sewing machine, in combination, stitch forming mechanism including a whirl and means for operating the same, including a cam shaft and connections between the cam shaft and whirl, thread measuring mechanism, and means operated by said connections for operating said thread measuring mechanism.

4. In a sewing machine, in combination, a

, horn, a presser-foot for clamping the work .mechanism comprising a pull-ofi' member, an

actuator, a member movably mounted on said actuator and controlled as to its position thereon by the thickness of the work, and means adjustably mounted on said movable member for engaging and operating said pulloff member. 7

6. In a sewing machine, thread measuring mechanism comprising a pull-01f member, a presser-foot, a lever, means for operating said lever a slide on said lever means for connecting said slide with said presser-foot, and an adjustable plate on said slide for engaging and operating said pull-off member.

7. A lockstitch shoe sewing machine including, in combination, a straight hook needle and ashuttle having provision for supplying a shuttle thread, both located on one side of the work, and on the other side of the.

work a rotatable horn pierced at its end for the passage of the needle, a looper carried by the tip of the hornand adapted to form a loop about the hook end of the needle, a presser foot to force the work against the horn, mechanism for drawing back a loop of needle thread and setting the stitch, a pull-elf, means for operating the pull-off to draw thread from a source of supply, thread clamps located respectively on opposite sides of said pull-off, connections from the presser foot for controlling the amount of thread drawn from the supply by the pull-ofi' for each stitch in accordance with the thickness of the work, and means for operating said threadclamps to clamp the thread between the pull-ofi' and work while the pull-ofi' is operating and to clamp the thread between the pull-off and the supply while the stitch set-ting mechanism is operating.

In testimony whereof I aflix my signature.

JAMES H. REED. 

